Testing instrument



. May 20, 193 P. E. QHAPMAN TESTING INSTRUMENT 3 sheets-sheet 1 Filed June 23. 1922 May 20, 1930. P, CHAPMAN I 1,759,479

TESTING INSTRUMENT Fi1ed June 25. 1922 3 Sheets-Sheet 2- both; from which testing potentials were last derived. 7 7' I (here the number ofsections per group of ries'll or resistances Figure 3) are the same, they should all bealike. .NVhere they are difa 'ferentthen the potentialsgof thecoils in the I totalifpotential of the group willbefequal which it is balanced or i tojthellgroup agai paralleled;

Lof-the armeter should be in a general way of j thesame style of connectionasthe armature to be tested. For ithesalie of clearnessI have shownthe continuous connection common on .bipolar armatures only. It isobvious that I for testingsuch windmgsas wave, reentrant',

i f andfothers the armeter may have the connec o;"tions of the-potential'circuitsofsimilar char- -acter. 1' 2 l: 5 i A ballast resistance {l6 Figuresl and 8 may i a be inserted where neared f limiting: the

yoke willraise the self induction of the Emma,

d ture and enable higher F; to be used 1 without.

.I may provide a; yoke and'supply an alternatingcurrentfto it Via any suitable'leadsjtovthe line17.. Coils 21 shouldbe connectedito produce in the armaturebeing tested a counter vE F. 'to the sources of potential Connected to the commutator.' m 1- r it v t s still further modificationas shown in 5 f Figure 2 is to supply allthe testing currentinductivelylthrough a ring20' which would preferably have a polyphase winding; 1 21. 1 I- would "then"? connect the Findicating i devices 16 with or without s'huntslGfi to'the T commutator: [I mayiin this fmo'dification if the E; M; I F. "sinduced across the 'commu I tator sectionsfarenotsuitable for the indr ca ting devices interpo'se "transformers- 22] as in f shown The'operation oft-hammer isas follows:

"ga m nner that, each fingen'will'press on-i-a a A hen that section between whichthe short cirtransformer, raising (the demand on its pri- Lmaiy which j will light upf. the lampseries coils of the potential windings (as seconda-V -winding as say from side to side then the en- 1 inent until .the 'lampsushow brightest Hindi eating that the said'shortcircuit is then about {in line with the points of maximum potential 19,"19". ,Mixed con1'1ecti0'ns; will be indicated o I Qbyirregularitiesfiin the illumination of the,

lamps, as for instance a pairof'leads crossed,

It "s desirable the potential circuits "lampsfldwhen testinganormal armature;

" normal or working potential- I may proporting bushing 23 fittingthearmature shaft, or other approprlateconnection is, used as h v ,7 orderrto-insulate thefgroundi'detectoi from across the SQCtIOIIS Of the commutatorthan i 1former 27. ,v m .7 I I "The i'ndicatoia's' lamp 28 may be either in Th m f lffi of the armature 6 151 switch i33 tothe ground bushing 2 3.'- Thi's. I" v ipla'cediin'thefingers of the'armeterS'in such d i i i i-g e'n't, the bushingi23 acting as a guide. 'fWhen"alternating current'is supplied, if,

th'ereg are no short fcircuits' the' in'dicatin'gide f'gvice's as lampsf16 will' all lightup part way.

If 't here is ashort circuit between alsection, H v 'incontactwithfinger8 .)-Iniorder ltoailoid 'cuitoccurs willdemandmore'curr'entlfrom its I v V I Q test just described I prefer .to open all other presencejjof a ground. butjnot its. location. 9 changing said switch 33 to the, contact i therewithmore'orless as the 'occasion mayide {hand Should there be an opencircuity'thef V t v "There are ethe modifications?thatl ma V IIOrmaIjdeInandQfOr cnrrent through the windf make in am 'groundjdetector;circuits-with ing willbe interrupted and the lamps'instead of lightingup partway will remain extintireset or a group'of lamps'woulcl light up i more or lessv according to location. thereoiy WVhere the apparatus is made single phase, 2

the armature should be rotated inthe instru Q 180 two lamps Would show dirn with a normal one between the same. 1 ;For comparison I may provide a pilotlamp i I v a '24 whose temperature may be adjusted'bythe V rheostat 25V to the" color; of'the indicating ,7 Q

" It 'isdesirable to test each armature simulf taneously for'grounds and at approximately vide a ground detector. to do this; 5 A'supone terminaljoflthe detector. I {'preferfin thesiipply circuit'to feed it through'v atra'nsseries with the primary 29 or secondaries 30, i 31 as desired; 11 haveshown it in the prit r F mary 29. One .endof the ground trans- $109 former secondary (31) is'connected to a point of the armeter circuitslat mid potential point.

as 32the other via finepartof secondary 30 a "and sWitc'hf33 toguideflbushing 23.", Thus "the interference of other testing potentials 1 will beminimized.

VVhlle thenormalpotentialground test just 7' I describedwiH givethe insulation of the armaswi tchr ests nornrially in contact :with the'end 7 of the secondary nO which willindicate the V 7 31 and rotating thearmature the ground may be located for the "lamp 28- will light up more or lesswlien thegroundedeectiorr'cornesj confusionwhen making the 'gfon dqo a in circuits andI ,may 'd'oi'this thefback con tacts 34. on; the 'groundjjlojcati'ngswitch: 3.-

out departingofroin the spirit of this j.Another test Which-it is desirable tonake is 'for the angular position of the commutator with reference to the ijndings with Which t is connected commonly called lead or com 7 mutator lead. a

' v In tliis'instruinent I may make this test by numbe of different methods each one of Which'being a preferred form. iii-its particular range of usefulness. VJherethe choke core 20 is, present either with or without counter E. Mi F. Windin'g2l I prefer to supply one or more of the slots35 thereof "with an explore-,- iiig coil preferablyone for: eachflside of the coil to be tested 36, 3'6" and to interconnect them. These windings may be loaded as with an indicating device37 or even; directly short oircuited. {If the indicating device 379's used it is preferable to place it iii uxtaposition to V the indicator or indicators l6 -Wl1i6liindicate other conditions of the particular mature coil Whose lead tothe commutator is tofbe' nected in series o-ne end-thereofjbeing connected ia lamp 37, to lower contact of switch 38,;the other to the top contact thereof;

The operation is as follows 'Upon closing the switch 38-thecurrent'nfillbe induced in each side of the armature: coil asYb-yI'this ,ineans ihe commutatorflead will be: deterthearnia'ture coil] 39'.

ininec to both the degree thereof, Whether forward or backward and'asto the'. span'fo t with this arrangeirient-fsliould the sets of the coil not'agree with tliatfpredeterniined by the position of'the e2; ringcoils36, ;3'6 the indication of the indicators :ltlwould be less, than usual tor the energy ndemanded by v the exploring co ls will then be taken from I coils in di'lferent slotsindicatii'ig than the usual indicators; v a The explor ng COllS mEvYPI'OClHCG a; disturb-- i said crossdisturbance} Y a wishto claim I r y In armature testing instrument, the combinat on ot a plurality oftransformers,

,With their primaries.

" de i-ceto be tested. I I -V 7 l. In aiiarmature testinginstrunieiiflj'the' combination with afpluralityof transformers of indicating devices connected in serieswith said plurality of transformers Whose sec 7 between each of said secondaries for malt" 1 connection to the article to be tested; e; ance: in other indicators than thefones" 'desired owing'totwo halves of different coils as 39. and'O beiiig" in the "SQIIlIGI'SlOl'iI Toneuf tralize this cross disturbance "I .iiialyl'put halancingi-coils" ll in the choke core slots that are opposite to the" disturbing coil (as or'coils, and supply a: potential to then jtroni any convenient source wlii' hf will 'neutralize 1+ igure 3 is a'inodification 'oI" -hisfapp'aratu's "useful in some cases with either A. C. or D. C.

V in which i the characters denoting the "same parts are the same as above. The transform-' ers have been eliminated and the indicators 16 placed' in series witlifeach other. Fingers 8 connected between each pair of indicators connect same infpara'll'elflwith the commutator, segments 7 Shunts h nay be provided as-above I I I The necessary plurality of sources 0t poteiitialfor successful testing after the man- 'ner herein are obtainedby the potentiometer drop across the armature section, the ,correspending indicator 16 'and its shunt} (if any) 1 Ei-in this typeot my device; The apparatus is'fed with current froinli'ne l7 iliar'y or ballast resistance 46. f e

the manner }hereiii,-be they transformer,

"orfpotentioineter type as'shoWn in Figure 3.

' The operation ofthis nodification is exact- Figure 1, except that thein ications are re- VQ-ISQCl, lZllfill 1's enope'n c rcuit would indicate bright; short circuit by Whole or partial extinguislinieiit etcg l A short through" the V Windingwou-lcl' of" course short circuit-theindicato'rs extinguishing the same; the balast resistance 4:6 takingupythey line voltage;

7 5 through auX- ly si ni-l-ar to that oi the device as shoW'n'inj l-lavinq. now described my "inventionfl haying theirsecondaries connected, and current indicators connected in series with their primar'ies. p a r k 2. Iii anarinature. testing instrument, the combination of a plura'lity of transformers v havingtheir secondariesconnected in series and current indicators connect'edfin'"series.

an armature testing instrunienty the comb nation of a plurality oi" transformers 'ondaries are connectedtogether andxineans i i 5.,In an armaturetestinginstruinent;the" combination with apluralityof transformers on dari'es for niaking to be tested.

":6; Infan. rmature te 1 11 c e o s r s ntt ie f combination of 1a plural ty of transformers J having their-secondaries connected Whose "primaries are connected in multiple, current indicators "mariesi.

connected in series with their pri- In an armature te'sting instri'ini'ent, the combination "of groups ofsection'al potential producing" circuitsyimeans'for varying the potentialit -said; groups so that theltotal potential-maybe the same in each group,.al-

- i 18;; In an though the 'numberjof sections are not the" same per group, indicating devices ,for each section, Y

armature testing instrument, the

a combination of apluralityoftransformers 9; In an o which have their secondaries connected, cur rent'indicators connected in series with their 7 [primaries and shunts jacross the said'indicm' armature testing instrument, i the combination: of a plurality of transformers Whose secondaries are connected, said transformericonnections being polarized to pro- 7 duce points offmaXim-um potential" corresponding tothose ofthe deviceto'be tested; 10.; In an -armature testing instrumenhth'e' combination, sofa plurality oftransfor mers, indicating devices inseries with 'the' pri- 1 mariesjgthereof, secondaries 'ofwsaidtransformers connected together and transformer v i l 30' connections being polarized to produce pointsof maximum potentialcorresponding to those of the device to he tested.

11. Inan armature testing v combination a of 'a plurality of trans-formers 7 whose secondaries are connected together, means between-each secondary for connecting thefdevice to be tested'thereto, andiconnections for said transformers'to producepoints v of maximum potential corresponding to' those "of the device to jbe tested.

a 12,111 anarmature testing instfiim nathe combination of an indicating device series 'wltha plurality oftransforniers hose secondaries are connected together; means hetween the secondaries for connecting" the de j vice tobe tested thereto, connections for said transformersto produce points of maximum '1 potential correspo ding to those of the-device l .tohetes'ted.

f 13. Inan armature testinginstrument; the

j cornbinationlof a plurality of 7 transformers combination of" osese eadarl o whose secondaries are cumulatively connected 7 together in series to form groups, said groups 1 being connected in normally balanced opposn i; 14,1In' anarinaturetesting instrument, the

- combination of a plurality of. transformers, whose secondaries fare cumulatively connected in series tof f ornfigroups said groups being i connectedinjnormally'balanced oppositioncto V produce polar'potentials similar to thoseof 5 thefdeviee tofbe'testedf' l 15. In an armaturei testlng ielmi lat ly e m ed 'bination' e timate plurality of. translfo'rm'ersl connected in normally balanced iopposition'to produce polar potentialslsimilar to thoseof the devicetto be testedand means between said secondaries for connecting the device to be tested.

16. In an in: series to form groups; said groupjsfbeing F7 V armature testing instrumengthe' con binatioirof means for testlng an, armat-LII'GCOIIIPIlSlIlg indicatingdevices connected 1 i w th potential; producing CII'CHItS- sections of said circuits being connected in a similarman ner to the windings of said armature, I

17 In an armature testing' nstrument, the

combination-0f means for testing an armature comprising ndlcating devices connected With.

groups of potential;producing circuits sections of said circuits'being connectedin a} similarmannerto said windings.

- 18; Inan'arm'ature testing lnstrum nhthe combination of means for', testing an arma? turecompr sing ind cating devices connected o 7' With groups f potent al' produc ng circu ts. in

sections of said "circuitsbeing connected in a: 7

similar manner tosaid armature, said groups a 1 being connected-to produce polar potentials j 's11n1lar-t o those of said armature 19.. Injatesting instrument thecombination' of a plurality 'of sets o f, transformer Windings having a common-core; with ashunt core {adapted to shunt any'irregularity in the magnetism linkedwithany set of the said ings around other'sets.

'20. In an armature testing instrument,the

combination oi meansfor. inductively produc V V 10 i'ng a testing potential in'the windings of'an armature having a p1ara1it .of sections, in-

di'cating devices one foreachof said sections i of saidarmatnr'e, and means for connecting 'sai dsections-to said;indicating device, includ 111g transformers linking said indicating" dev ces andsaidsectlonsffl 21'. uln an armature'testinginstrumenti combinationiof a resistance having'taps at;

' suitable portions, means for connecting said res stance'taps to a plurality of'armature-sec tions and an'indi'cating device'connected w th each of said sections.

f t re; ng-assumethat' 424. In an armaturetesting instr combination'of means'ffortesting thewin ing O i' mat and a ho e C iQaS O ivith the corefof-said armatureiof V" I r ing the self induction ofsaidfarmature. j 125; i In fan 7 armatureitesting instrument combination of means for testing the winding of an armature and of a toothed choke core associated with the core of said armature for increasing the self induction of said armature. 26. In an armature testing instrument, the combination of means for testing the winding of 'an armature and means" for applyingv a counter E. M. F. to the winding of thes'aid. armature consisting of a core associated with the-said armature core having exciting windings applied thereto.

27; In an armature testing instrument, the combination ofmeans for testing the commutatorlead, consisting of a choke core associatedwith the core of said armature,"an

exploring coil thereon with meansfor indicating the activity of said exploring coil.

'28. In an armature testing instrument, the combination of means for testing the'commutator lead of an armature consisting of an exploring coil a core therefor adapted to be associated with the core of said armature, with means for indicating which sections of the commutator are connected to the winding contained in the'slot associated with said exploring coil. I 29. In an armature testing instrument, the combination of means for testing the commutator lead of an armature consisting of an exploring coil, a core therefor adapted'to be associated with the core, of said armature, with means for indicating which sections 7 of the commutator are connected to the windexploring coil.

ing contained'in'the slot associated withsaid 30. In an armature testing. instrument, the combination of means for indicating the lead of the commutator ofian armature, consisting of means for "supplying a testing current to a section of said armature, a current indicator associated therewith, an exploring coil having a core adapted to be associated with the core of said armature. I

31. In an armature testing instrument, the combination of means for indicating the lead of thecommutator ofan armature, consisting of means for supplying a testing current to a section of said armature, a current indicator associated therewith, and an exploring coil having a core adapted to be associated with the core of said armature, an electric indicator associated with said exploring coil. 32; In an armature'testing instrument, the

ture using alternating current, means for testing the commutator lead of said armature consisting of a choke core associated with the core of said armature, and an exploring coil applied to the said choke core adapted'to-af feet a sectional indicator of said armeter.

34. The combinationof an armature testing instrument having a plurality of section indicators, a transformer for each section and means for connecting same'to the armature to be tested with a high frequency source of current supply.

r 35. In an armature testing instrument,

means for'testing an armature, comprising 1 means for applying a testing potential to the section of said armature, indicators for revealing currents that are caused to flow by said potential in said armature combined with means for testing the commutator lead of said armature. i v

In testimony whereof I hereuntoaffix my signature, this 7th day of June, 1922; I PENROSE E. CHAPMAN.

combination of means for testing the: com- 7 mutator lead of an armature, consisting of 

